Extended-Range Communication Preamble Repetition for Weak-Channel Decoding
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Solution Overview
Problem
Existing WLAN systems face limitations in extending communication range and reliability, particularly in environments with weak channel conditions, due to challenges in accurately transmitting and decoding preambles in wireless communication protocols like IEEE 802.11be (EHT).
Innovation Solution
Implementing a preamble structure with repeated patterns in the physical layer protocol data unit (PPDU) for extended range transmission, utilizing forward error correction (FEC) encoding and redundant bits to enhance accuracy and reliability, allowing receivers to combine repeated patterns for improved decoding success even in noisy channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional preamble structures are used in IEEE 802.11be (EHT) systems, then the system supports high throughput and multi-user access, but the communication range is limited and decoding reliability deteriorates in weak channel conditions
Solution Approach 1:
The preamble is segmented into multiple identical repeated patterns instead of using a conventional single structured preamble. Each repeated pattern contains the same signal fields (L-STF, L-LTF, L-SIG, U-SIG, EHT-SIG), allowing receivers to combine multiple instances for improved decoding reliability in weak channel conditions while maintaining compatibility with existing WLAN standards
Solution Approach 2:
The patent creates multiple copies of the entire preamble structure and transmits them in sequence. This copying approach allows the receiver to accumulate signal energy across multiple identical transmissions, significantly improving detection and decoding reliability for extended range communication without requiring complex new preamble designs
2Length of moving object
If repeated patterns are added to extend communication range, then coverage is improved, but transmission overhead and complexity increase
Solution Approach 1:
The preamble is divided into separatable repeated patterns that can be independently transmitted and combined. This segmentation allows the system to extend communication range through multiple repetitions while maintaining flexibility in configuring the number of repetitions based on channel conditions, thereby managing transmission overhead efficiently
Solution Approach 2:
The patent changes the parameter of preamble repetition count to extend communication range. By adjusting the number of repeated patterns based on channel conditions and distance requirements, the system can achieve extended coverage while controlling overhead, as the same data is transmitted multiple times rather than requiring additional error correction bits
3Reliability
If conventional error correction is used, then some reliability is achieved, but decoding success rate is insufficient in noisy channels with extended range
Solution Approach 1:
The patent merges multiple identical preamble transmissions by combining their signal energies at the receiver. This combining approach significantly improves decoding success rate in noisy channels by accumulating signal power across multiple repetitions, achieving enhanced reliability without requiring complex forward error correction schemes beyond what is already in the IEEE 802.11be standard
Data Source
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AI summary
A wireless communication method performed by a first apparatus comprises generating a first signal field having a fixed length; generating a second signal field having a variable length; and transmitting a physical layer protocol data unit, PPDU, including the first signal field and the second signal field to a second apparatus, wherein said generating the second signal field comprises: generating a bitstream; generating an encoded block by encoding the bitstream; generating a modulated block by modulating the encoded block; generating, from the modulated block, an orthogonal frequency-division multiplexing, OFDM, symbol block including at least one OFDM symbol; and arranging the OFDM symbol block and one or more repetitions of the OFDM symbol block within the second signal field.